02 Levels and my Apnea

[robpeet]

I am new to CPAP. Been trying to get used to the machine for the past month, without much success.

I recently purchased an Oximeter/Pulsemeter. For the past three nights I have slept with the meter on and the cpap machine off. My 02 levels throughout the nights maintained a constant 02 saturation above 95%, and my pulse remained constant. I don't know what to make of this? Could the sleep tests I took under a stressful lab room have given my doctor an unreliable reading? ( My lowest 02 levels during my controlled sleep test never went lower than 88% )

I was under the impression that the main damage from Apnea was the constant ''stop breathing'' events, thus depriving my body and brain of 02. If I in fact stop breathing during my sleep cycle, would not my 02 levels drop with a corresponding pulse rate increase?

I am curious if anyone on this forum has come across a question such as mine. Any input and/or explanation by anyone on this forum , be you a medical person or a layman/cpap machine user would be appreciated. I am confused about this matter. thank you.

[JDS74]

Robpeet

Welcome to the forum.

Could you post your equipment and the results of your sleep study?
It would be helpful to have the AHI from the study as well as the percentages of OSA, CSA, HYP events.

Some sleep apnea events don't last long enough to cause significant O2 desaturations but are frequent enough to really disturb your rest.

[jdr999]

RobpeetSome sleep apnea events don't last long enough to cause significant O2 desaturations but are frequent enough to really disturb your rest.

As stated there are two issues at play.

The first is the constant arousals which prevent us from deep, rejuvenating sleep. You don't need to desat at all during an arousal but they can still greatly affect your quality of sleep.

The second issue is the O2 desats themselves and how they can damage our bodies.

[robpeet]

Please bear with me. I am a newbie.

I guess I am not quite understanding your explanations. When I took the sleep test I was told that I stopped breathing 20 times per hour when I slept on my side, and 85 times per hour when I slept on my back. ( I only slept on my back for the test. Otherwise I never do )

If my own readings are showing a constant level of 95% O2, I don't see where the sleep interruptions occur. Surely if I stopped breathing for 3-6 seconds for example, my O2 levels would drop to where I would see an indication on the graph lines, and I would see a rise in my pulse since I am gasping for return of air. Is this Not correct, in your opinions?

[zoocrewphoto]

Please bear with me. I am a newbie.

I guess I am not quite understanding your explanations. When I took the sleep test I was told that I stopped breathing 20 times per hour when I slept on my side, and 85 times per hour when I slept on my back. ( I only slept on my back for the test. Otherwise I never do )

If my own readings are showing a constant level of 95% O2, I don't see where the sleep interruptions occur. Surely if I stopped breathing for 3-6 seconds for example, my O2 levels would drop to where I would see an indication on the graph lines, and I would see a rise in my pulse since I am gasping for return of air. Is this Not correct, in your opinions?

There are a lot of factors that can make situations very different. Here's my example. I am considered severe with an average ahi of 79. A little higher on my back (89). Not sure about REM as I did not reach REM during the diagnosis phase. That said, my oxygen saturation only went below 90% for 13% of the night. The mean oxygen saturation for my diagnostic study was 94.5%. By oxygen standards, I wasn't that bad. But that is because I have LOTS of short apneas. My brain is very good at waking me up quickly enough to prevent my oxygen from going lower. But that means that my sleep cycles are trashed. During that diagnostic study, I didn't even reach deep sleep, let alone REM. I was too busy waking up, again, and again, and again.... Also, the way my brain wakes me up us to release adrenaline, which raises my blood pressure and leaves me at a higher risk of stroke and heart attack.

What machine do you have? Does it have data available to you? If so, you can see what it is doing for you and how much it is helping. Even an ahi of 20 is moderate. You are waking up, on average, every 3 minutes. That is not good quality sleep.

There is a LOT to be gained, even if your oxygen doesn't go down much. There is a lot more to sleep than one factor.

[-tim]

My 02 levels throughout the nights maintained a constant 02 saturation above 95%, and my pulse remained constant. I don't know what to make of this? Could the sleep tests I took under a stressful lab room have given my doctor an unreliable reading? ( My lowest 02 levels during my controlled sleep test never went lower than 88% )

I was under the impression that the main damage from Apnea was the constant ''stop breathing'' events, thus depriving my body and brain of 02. If I in fact stop breathing during my sleep cycle, would not my 02 levels drop with a corresponding pulse rate increase?

I am curious if anyone on this forum has come across a question such as mine. Any input and/or explanation by anyone on this forum , be you a medical person or a layman/cpap machine user would be appreciated. I am confused about this matter. thank you.

What is normal when you are awake? If it is 99 or 100% then 95% can result in "lightly drunk" like thinking for some people. Your SpO2 device should be seeing massive drops as you move since they tend to be very poor sensors while the expensive medical grade ones tend to be better. Your pulse should also change during your sleep. If everything looks very constant, I would question your device.

I guess I am not quite understanding your explanations. When I took the sleep test I was told that I stopped breathing 20 times per hour when I slept on my side, and 85 times per hour when I slept on my back. ( I only slept on my back for the test. Otherwise I never do )

If my own readings are showing a constant level of 95% O2, I don't see where the sleep interruptions occur. Surely if I stopped breathing for 3-6 seconds for example, my O2 levels would drop to where I would see an indication on the graph lines, and I would see a rise in my pulse since I am gasping for return of air. Is this Not correct, in your opinions?

Your AHI is 20 on your side and 85 on your back. It should be less than 5 in either position.

Put on your SpO2 and hold your breath.... Notice how it doesn't go down quickly? A 30 second apnea isn't going to show up on its data but it will wake you up and that causes stresses that effect your heart and seem to cause the circulatory system to be less flexible and that may lead to an increase in stroke risk. The O2 at 95% won't have a major impact but drops below 88% can lead to organ damage. The poor sleep increases your risk of accidents as well.

[robysue]

robpeet,

Some sleep docs simplify the sleep test results way, way too much.

There are several kinds of respiratory events that are recorded during a sleep test and not all of them require a clinically significant drop in O2 levels to be recorded. These events include:

Obstructive Apnea: A total cessation of air flow going into and out of the lungs for at least 10 seconds while effort to breathe is still being made. In order to "count", the OA has to start during a time a time when the EEG says you are asleep. An O2 desat may or may not occur with an OA. For people who don't desat, the OA usually ends with an EEG arousal before the O2 desat can occur. The problem in an OA is a collapsed airway.

Central Apnea: A total cessation of air flow going into and out of the lungs for at least 10 seconds when no effor to breathe is being made. In order to "count", the OA has to start during a time a time when the EEG says you are asleep. An O2 desat may or may not occur with a CA. For people who don't desat, the CA usually ends with an EEG arousal before the O2 desat can occur. The problem in a CA is that the brain forgot to send the signal to breathe.

Hypopnea: Loosely a hypopnea is a significant decrease in the amount of air flowing into and out of the lungs that lasts for at least 10 seconds. The decrease is measured relative to a baseline airflow that is computed over several minutes of "normal" breathing. In order to "count", the hypopnea has to start during a time a time when the EEG says you are asleep. The usual assumption is that the diminished air flow in a hypopnea is caused by a partial collapse of your upper airway. It's often described as like trying to breathe through a very small straw.

Scoring of hypopneas on NPSGs is, unfortunately not uniform. The sleep docs diagnosing us with SDB all believe hyponeas should be counted---or at least some hypopneas should be counted, but which ones should count still seems to be a bone of contention. Which is why we've got the confusing mess of the American Academy of Sleep Medicine (AASM) having two official definitions for scoring hypopneas: The AASM Recommended Standard and the AASM Alternative Standard for hypopneas. See http://www.ncbi.nlm.nih.gov/pubmed/19238801 and http://www.journalsleep.org/ViewAbstract.aspx?pid=27368 for a scholarly discussion of how and when these two standards affect a patient's diagnosis of OSA as well as the formal definitions of the two standards:

• AASM Recommended Standard: A hypopnea requires at least a 30% reduction in airflow for at least 10 seconds AND a corresponding O2 desaturation of at least 4%. Such a hypopnea does NOT require an EEG arousal
• AASM Alternative Standard: A hypopnea requires at least a 50% reduction in airflow for at least 10 seconds AND one or both of the following conditions: A EEG arousal OR a corresponding O2 desaturation of at least 3%.

If you look at these definitions of the kinds of events that make up OSA carefully, you will notice that it is possible to have an OSA diagnosis based on a sleep test with huge numbers of events and NO official O2 desats. (It happened to me.) All it takes is for you to be an OSA sufferer who tends to arouse before the O2 desats have a chance to occur. The thing is all those arousals to kick start the breathing and prevent the O2 desats are disturbing to the sleep cycles all by themselves and prevent you from getting good quality, restorative sleep. What happens during all these arousals is that all kinds of stress hormones get pumped through your body and, of course, you get bumped out Stage 2, stage 3 or REM sleep up to Stage 1, or Wake very, very briefly (too briefly to remember waking up). The stress hormones can trigger low level inflammation throughout the body and that can also damage your body. Perhaps not as much as repeated O2 desats, but it's still damage. (There are some interesting studies that are beginning to link heart disease to low levels of chronic inflammation for example.)

[Todzo]

I am new to CPAP. Been trying to get used to the machine for the past month, without much success.

What comes to mind is that you might spend some quality time with the machine during the day. Some of it on your bed learning to breath quietly. The machine will tend to make you breath more air because of the pressure. With your conscious mind you can help move that back to the levels you use when not using CPAP.

It is also a good time to test mask fit and work out hose management issues as you move to all your normal positions.

Then some time watching light TV, or books, or music. Some time during the day with distraction so the machine becomes normal to you.

You are building a new set of “chemoreflexes” so this will take about the time it took for you to learn to throw a ball, or catch, or learn another sport. A bit of time each day.

FWIW if I see problems in my CPAP data (I look at my data several times a week) I will often spend some quality time during the day and it always seems to help. I have been doing this for ten years now.

Recently I have learned that it is wise to check your vitamin D levels. Those who are working with the D3 hormone (A.K.A. Vitamin D3) (e.g. Dr. Stasha Gominak, Michael F. Holick, Ph.D., M.D., Vitamin D Council) seem to be finding that the very low side of the “normal” range of 30-100 ng/L produces a range of symptoms including OSA, pain, and infection. All believe that a level lower than 50 ng/mL is not good and Dr. Stasha Gominak recommends 60-80 ng/mL for good health.

I recently purchased an Oximeter/Pulsemeter. For the past three nights I have slept with the meter on and the cpap machine off. My 02 levels throughout the nights maintained a constant 02 saturation above 95%, and my pulse remained constant. I don't know what to make of this? Could the sleep tests I took under a stressful lab room have given my doctor an unreliable reading? ( My lowest 02 levels during my controlled sleep test never went lower than 88% )

There are four things about the current implementation of the so called “golden standard” sleep test that bother me.

First, it is done in the laboratory. Do you normally sleep in a laboratory? Was your normal “go to bed” routine upset by going to the laboratory? If you want so see how a person normally sleeps I do believe you will need to test where the person normally sleeps!

Second the test is very expensive. This means that it is very likely that you will only get one shot (often half a shot) to get the data that you are going to use to make the diagnosis. But after looking at my CPAP data for several years now I can tell you that I never sleep in the comfort of my own bed the same any two nights!! I really do believe that to get an accurate look at how a person is sleeping you will need to do the test in the home over a period of several nights.

Third all the wires and all tend to be uncomfortable and restrictive. We do not normally sleep with all this stuff attached. I do believe that technological advancements are more than possible with our current technology – but – we have an industry that is “making a lot of gold” doing things as they have done them for several decades now.

Forth, because of the upset of going to and being in a laboratory, because the test is so expensive, because it is such an all important “one shot” deal, and because it involves our basic health and welfare there is a lot of stress associated with this one night in a lab. Looking at my own data (I use CPAP data, pulse oximeter, and nighttime audio to check how I am sleeping) I know that stress has the greatest effect on how I sleep any given night.

“First night effect” is well known and documented.

I do believe your results could be different in your own bed vs the lab on “one expensive shot” night.

I was under the impression that the main damage from Apnea was the constant ''stop breathing'' events, thus depriving my body and brain of 02. If I in fact stop breathing during my sleep cycle, would not my 02 levels drop with a corresponding pulse rate increase?

Please note that the sensor is on the finger tip. An extremity of an extremity. When we have an apnea or hypotnea our body responds by releasing stress hormones. As well, our breathing levels are likely to change and so change our blood chemistry. The bodies stress response changes the blood flow in the extremities in major ways. Stress is well known to decrease the blood flow specifically to the extremities.

From my own experience I know that I can “breath out gently and stop” - for thirty seconds – while watching my pulse oximeter at my desk – and see no more than a 2% change in my SpO2 reading during the thirty seconds of the stop and the following thirty seconds. I have done this many times. For that matter I have learned to breath eucapnically and 30 seconds is less than the time needed for me to feel any sort of a strong urge to breath.

The very fast drops in blood oxygen level caused by OSA are likely caused by a combination of our extremity starving stress response coupled with the changes in blood chemistry which result from over shoot “recovery breathing”. Although I have asked question of why SpO2 drops so rapidly with OSA many times no doctor would answer it.

All of this said the pulse oximeter is know as a crude way to diagnose OSA. It will not pick up subtle events.

I am curious if anyone on this forum has come across a question such as mine. Any input and/or explanation by anyone on this forum , be you a medical person or a layman/cpap machine user would be appreciated. I am confused about this matter. thank you.

Yes, I have seen the issues you raise many times. OTOH – that is from many forums over six or so years.

[sleepy1235]

I had a very close friend who had a problem with insomnia.

I drove him to and back from a sleep test. The nurses were joking that everyone that comes there gets diagnosed with Apnea.

He was diagnosed with apnea.

He was retested elsewhere and he didn't have apnea. He was young, not overweight, and had no indicators for apnea. The doctors were very puzzled why and how the first doctor diagnosed apnea.

So if you are in Texas, you might consider a 2nd study.

[Todzo]

I had a very close friend who had a problem with insomnia.

I drove him to and back from a sleep test. The nurses were joking that everyone that comes there gets diagnosed with Apnea.

He was diagnosed with apnea.

He was retested elsewhere and he didn't have apnea. He was young, not overweight, and had no indicators for apnea. The doctors were very puzzled why and how the first doctor diagnosed apnea.

So if you are in Texas, you might consider a 2nd study.

perhaps the lab has a mold problem

[sleepy1235]

Perhaps the doctor is incompetent and likes the cash flow.